In recent years, in order to perform analysis of trace amounts of substances such as proteins or nucleic acids with high accuracy and at high speed, microchannel chips have been used. The microchannel chips have an advantage of requiring smaller amounts of reagents and samples and thus are expected to be used in various applications including clinical inspection, food inspection, and environmental inspection.
In order to automate processing using the microchannel chip, providing a valve structure in the microchannel chip is proposed (refer to PTL 1, for example).
PTL 1 discloses a microchannel chip having a microvalve of a diaphragm valve structure which opens and closes a channel by changing the shape of a side wall of the channel. In the microchannel chip, a second channel is formed in the vicinity of a first channel. When pressure of a fluid in the second channel is increased, a wall (a diaphragm) of the first channel, which is located between the first channel and the second channel, is deformed so as to block the first channel. Therefore, the fluid flow in the first channel can be controlled by adjusting pressure to a fluid in the second channel.